EP 0282236-A1 reports that a dibenzothiazepine derivative can be processed to give 11-[4-(2-(2-hydroxyethoxy)-ethyl]-1-piperadinyldibenzothiazepine derivative, which is of value as, for example, an antipsychotic pharmaceutical. In more detail, dibenzo-[b,f][1,4]thiazepin-11-one, which is a representative compound of the dibenzothiazepine derivatives reported therein, is reacted with phosphorus oxychloride to yield a 11-chloro-dibenzothiazepine derivative. To the 11-chloro-dibenzothiazepine derivative is added piperazine to yield a 11-piperazinyl-dibenzothiazepine derivative, which is subsequently reacted with 2-chloroethoxyethanol under basic conditions to give the desired 11-[4-(2-(2-hydroxyethoxy)-ethyl]-1-piperadinyldibenzothiazepin.
EP 0282236-A1 further reports that the dibenzo-[b,f][1,4]thiazepin-11-one is prepared from phenyl 2-(phenylthio)phenylcarbamate or its analogous compound by cyclization in the presence of polyphosphoric acid.
Helv. Chim. Acta., 1959, 42, 1263 reports that a dibenzothiazepine derivative can be prepared by heating a methyl thiosalicylate derivative with a 2-halogenated nitro-benzene derivative in the presence of sodium to give a 2-nitro-2′-carboxy-diphenylsulfide derivative, which is then reduced using a Raney-nickel catalyst to yield a 2-amino-2′-carboxy-diphenylsulfide derivative, which is finally heated to give a dibenzothiazepine derivative.
Org. Prep. Proced. Int., 1974, 287 reports that a dibenzothiazepine derivative can be prepared by heating a thiosalicylic acid ester derivative and 2-iodo-nitrobenzene derivative in the presence of sodium methylate and copper, treating the resulting compound successively with an alkaline solution and an acidic solution to give a 2-nitro-2′-carboxy-diphenylsulfide derivative, reducing the derivative by ferrous sulfate in an aqueous ammonia solution to give a 2-amino-2′-carboxy-diphenylsulfide derivative, and heating the resulting derivative under reduced pressure.
WO 92/19607 reports that a dibenzothiazepine derivative can be prepared by the steps of reacting 2-amino-thiophenol with 2-fluorobenzonitrile to give 2-(2-amino-phenylthio)benzonitrile, hydrolyzing the resultant compound to give 2-(2-carboxyphenylthio)aniline, and finally cyclizing the aniline derivative.
As described above, various processes for preparing a dibenzothiazepine derivatives are known. However, the known processes have various disadvantageous features such as a low yield, high temperature reaction conditions, use of starting compounds which are not easily available, and/or complicated post-treatment. These disadvantageous features are naturally unfavorable in the industrial preparation of the desired dibenzothiazepine derivative.
EP 1201663A1 and WO 2004/047722 A2 also report preparation of dibenzothiazepine derivatives.